Hillary Clinton was forced to leave a 9/11 commemoration ceremony early Sunday after she reportedly fell ill, NBC News reported. According to a statement from Dr. Lisa R. Bardack, Clinton's physician, the candidate was diagnosed with pneumonia on Friday and prescribed antibiotics.

JUST IN: @HillaryClinton's doctor says she was diagnosed with pneumonia on Friday &amp; put on antibiotics.

As NBC News previously reported, citing "two senior law enforcement officials," Clinton may have fainted shortly before leaving the ceremony by van.

JUST IN: Hillary Clinton became ill, may have fainted during 9/11 memorial that she was attending in lower Manhattan, sources tell @NBCNews

According to CNBC, Clinton campaign officials released a statement saying Clinton left the ceremony after 1 hour, 30 minutes because she "felt overheated," and immediately headed to daughter Chelsea Clinton's apartment to rest. A campaign spokesman added that she's now feeling much better, which Bardack confirmed, attributing the incident to Clinton's being overheated and dehydrated.